Harnessing genotype-by-environment interaction and stability analysis of taro (Colocasia esculenta (L.) Schott) genotypes for resilient breeding and food security in Southwest Ethiopia.

BACKGROUND: Taro (Colocasia esculenta (L.) Schott) is an important staple in southwestern Ethiopia, contributing to food security and adapting to marginal environments. Understanding genotype-by-environment interaction (G × E) is essential for identifying stable, high-yielding taro genotypes for resilient breeding and food security in Southwest Ethiopia. However, its G × E interaction and stability remain under-researched in Southwest Ethiopia. METHODS: Ten taro genotypes were evaluated across six environments using a randomized complete block design with three replications. Yield and related traits were assessed using Additive Main effects and Multiplicative Interaction (AMMI), GGE biplot models, and Genotype Stability Index (GSI) analyses. RESULTS: AMMI analysis showed environment was the main source of variation for all traits, except cormel weight, where genotype had a greater influence. The genotypes x environment interaction (GEI) effects contributed less to the total variation but were still notable. Based on the Genotype Stability Index (GSI), Kiyaq and SM/Ce65 were the most stable genotypes with a high total yield, whereas JD/Ce17 and KD/Ce50 were unstable and low-yielding genotypes in all environments. According to the Which-Won-Where analysis, JS/Ce06 and JD/Ce23 outperformed all other genotypes across environments, with the exception of Jimma. JD/Ce23 had the highest mean yield (37.56 t/ha) and high stability, making it a promising genotype for wide adaptation. The GGE biplot identified JD/Ce23 as the ideal genotype due to its high yield and broad adaptability and recommended it for further evaluation under farmers' conditions prior to potential release. The GGE biplot analysis identified two distinct mega-environments and delineated that Tercha and Gera were the most discriminating, while Jimma was the least. Tercha was identified as the ideal site for evaluating taro genotypes for yield traits. CONCLUSION: The study provides insight into taro G × E interaction and stability, supporting genotype selection for resilient breeding and enhanced food security in southwestern Ethiopia. These findings contribute to expanding taro genetic resources and inform breeding strategies aimed at enhancing both crop resilience and regional food security.